1. Field Of The Invention
This invention relates to a method and apparatus for restraining cargo. More particularly, this invention relates to a method and apparatus for restraining wheeled carts and other cargo transported by trailers.
2. Description Of The Related Art
Trailers and semi-trailers (collectively “trailers”) are used to haul cargo over long distances. Full trailers have front and rear axles and are coupled to a towing truck by a drawbar. Semi-trailers (“semis” for short) lack a front axle and so must be supported by legs (“landing gear”) when not coupled to a towing truck, typically by a fifth wheel coupling. The fifth wheel coupling is a large flat plate bolted to the rear truck chassis on which the semi-trailer rests and pivots.
A typical trailer has a rectilinear interior or compartment defined by a front wall or bulkhead, side walls, a ceiling, floor and rear doors. The interior walls and floor may be lined with plywood, hardwood or any other suitable material and reinforced with posts or beams. The rear doors may be sliding doors, swinging doors or any other suitable door or doors.
The cargo, whether it be large individually packaged products or smaller products packaged in groups, must be secured within the trailer compartment to prevent damage to the cargo or, worse, cargo falling from the vehicle. Numerous means have been developed and used over the years for restraining cargo within a trailer, including tie down straps and chains (U.S. Pat. Nos. 5,302,064 and 7,476,070), cross bars and rods (U.S. Pat. No. 5,370,482), partitions (U.S. Pat. No. 7,445,412), adhesive restraining strips (U.S. Pat. No. 6,089,802) and expandable gates (U.S. Pat. No. 6,939,096).
With the adoption in 2004 by the Federal Motor Carrier Safety Administration (“FMCSA”) of stricter cargo restraining rules, motor carriers have been exploring alternate ways for restraining cargo that comply with the new rules, assure worker safety and protect the cargo being transported. Under the new rules, cargo must be immobilized or secured in accordance with general securement rules or commodity-specific securement rules. These securement rules provide that the cargo securement systems must withstand forces caused by trailer deceleration in the forward direction and acceleration in the rearward and lateral directions. Deceleration is the rate at which vehicle speed decreases as the brakes are applied, and acceleration is the rate at which vehicle speed increases in the lateral (sideways) direction when the vehicle is turning, or in the rearward direction when the vehicle is being driven in reverse and makes contact with a loading dock. Deceleration/acceleration forces are commonly measured as a percentage of the force of gravity (g), where 1 g equals 32.2 feet/second/second, or 32.2 ft/sec2. The FMCSA requires that cargo securement systems be capable of withstanding the forces associated with three deceleration/accelerations: (1) 0.8 g deceleration in the forward direction; (2) 0.5 g acceleration in the rearward direction; and (3) 0.5 g acceleration in the lateral direction.
The present invention is intended to fulfill these objectives by providing an improved method and apparatus for restraining cargo, particularly wheeled carts, being transported in trailers.
More particularly, it is an object of the present invention to provide a cargo securement system that can secure wheeled carts having up to 42,400 lbs. per load.
Another object of the present invention is to provide a cargo securement system that decreases loading and unloading times.
Further and additional objects will appear from the description, accompanying drawings, and appended claims.